Allergic conditions in the past have been treated with a variety of drugs including those characterized as 1-alkyl-4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)-piperidines.
Prior to the present invention, it was known that the compound cyproheptadine of the structure ##SPC1##
Was an active antihistaminic and antiserotonin agent and was therefore useful in the treatment or relief of certain allergic conditions. This is disclosed in U.S. Pat. No. 3,014,911, Edward L. Engelhardt, which patent was issued Dec. 26, 1961.
The novel 1, 2 or 3-cyano compounds of the present invention are distinguished from the prior art patented compounds by their tranquillizing activity. In standard laboratory animals, the compounds of the present invention are found to have central nervous system activity characteristic of tranquillizing agents. Thus, in laboratory mice the compounds are shown to depress motor activity or in trained squirrel monkeys and rats behavioral evidence of tranquillizing activity of the compounds is observed.